package hr.infomare.joppd;

import java.awt.Color;

import java.awt.Graphics;

import java.util.HashMap;

import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.Element;
import javax.swing.text.PlainDocument;
import javax.swing.text.PlainView;
import javax.swing.text.Segment;
import javax.swing.text.Utilities;

public class XMLEditor extends PlainView {
    private static HashMap<Pattern, Color> patternColors;
        private static String TAG_PATTERN = "(</?\\w+)\\s*>?";
        private static String TAG_END_PATTERN = "(/>)";
        private static String TAG_ATTRIBUTE_PATTERN = "\\s(\\w*)\\=";
        private static String TAG_ATTRIBUTE_VALUE = "[a-z-]*\\=(\"[^\"]*\")";
        private static String TAG_COMMENT = "(<!--.*-->)";
        private static String TAG_CDATA_START = "(\\<!\\[CDATA\\[).*";
        private static String TAG_CDATA_END = ".*(]]>)";
     
        static {
            // NOTE: the order is important!
            patternColors = new HashMap<Pattern, Color>();
            patternColors.put(Pattern.compile(TAG_CDATA_START), new Color(128, 128, 128));
            patternColors.put(Pattern.compile(TAG_CDATA_END), new Color(128, 128, 128));
            patternColors
                           .put(Pattern.compile(TAG_PATTERN), new Color(63, 127, 127));
            patternColors.put(Pattern.compile(TAG_ATTRIBUTE_PATTERN), new Color(
                    127, 0, 127));
            patternColors.put(Pattern.compile(TAG_END_PATTERN), Color.red);
            patternColors.put(Pattern.compile(TAG_ATTRIBUTE_VALUE), new Color(42,
                    0, 255));
            patternColors.put(Pattern.compile(TAG_COMMENT), new Color(63, 95, 191));
        }

    /**
     * @param element
     */
    public XMLEditor(Element element) {
     
            super(element);
     
            // Set tabsize to 4 (instead of the default 8)
            getDocument().putProperty(PlainDocument.tabSizeAttribute, 4);
        }
     
        @Override
        protected int drawUnselectedText(Graphics graphics, int x, int y, int p0,
                int p1) throws BadLocationException {
     
            Document doc = getDocument();
            String text = doc.getText(p0, p1 - p0);
     
            Segment segment = getLineBuffer();
     
            SortedMap<Integer, Integer> startMap = new TreeMap<Integer, Integer>();
            SortedMap<Integer, Color> colorMap = new TreeMap<Integer, Color>();
     
            // Match all regexes on this snippet, store positions
            for (Map.Entry<Pattern, Color> entry : patternColors.entrySet()) {
     
                Matcher matcher = entry.getKey().matcher(text);
     
                while (matcher.find()) {
                    startMap.put(matcher.start(1), matcher.end());
                    colorMap.put(matcher.start(1), entry.getValue());
                }
            }
     
            // TODO: check the map for overlapping parts
             
            int i = 0;
     
            // Colour the parts
            for (Map.Entry<Integer, Integer> entry : startMap.entrySet()) {
                int start = entry.getKey();
                int end = entry.getValue();
     
                if (i < start) {
                    graphics.setColor(Color.black);
                    doc.getText(p0 + i, start - i, segment);
                    x = Utilities.drawTabbedText(segment, x, y, graphics, this, i);
                }
     
                graphics.setColor(colorMap.get(start));
                i = end;
                doc.getText(p0 + start, i - start, segment);
                x = Utilities.drawTabbedText(segment, x, y, graphics, this, start);
            }
     
            // Paint possible remaining text black
            if (i < text.length()) {
                graphics.setColor(Color.black);
                doc.getText(p0 + i, text.length() - i, segment);
                x = Utilities.drawTabbedText(segment, x, y, graphics, this, i);
            }
     
            return x;
        }
}
